Simulation of Aerodynamically Generated Sound Using Hybrid Aeroacoustic Methods
Regular paper
KTH Royal Institute of Technology
Monday 1 june, 2015, 15:40 - 16:00
0.7 Lisbon (47)
Abstract:
A numerical method to simulate aerodynamically generated sound and its
propagation is presented in this paper. The transient flow field solution is
established using a compressible 2D Navier Stokes solver. The source terms are
then defined by using Lighthill’s and Howe’s acoustic analogy, respectively,
which are evaluated from the flow solutions. The propagation of acoustic waves
from these sources is then performed using the wave expansion method (WEM). This
is a discretization method suitable for solving wave propagation through
inhomogeneous potential flows.
The method is tested on a flow of a rectangular open cavity. The flow conditions
are a free stream Mach number of M=0.5 and Reynolds number of Re=1500. At these
conditions the flow over the cavity is characterized by a periodic role up of
vorticity in the shear layer. As these vortices are then convected by the mean
flow and interact with the trailing edge of the cavity, acoustic waves are
created and propagate towards the leading edge, where the vorticity feedback
mechanism is started again.
The numerical results are compared to experimental and numerical results from
other studies of the same configuration.